This invention relates to a roll-up door and, more particularly, to a roll-up door having thermal protection means provided in the mounting arrangement of the side rails on opposite sides of the roll-up door, in which the roll-up door rides up and down during the raising and lowering thereof, and also provided by a heated hood arrangement disposed longitudinally over the support roller on which the roll-up door is rolled up into in the raised position thereof, the roll-up door also being provided with a direct drive gearing arrangement for the roll-up and roll-down mechanism, the direct drive gearing arrangement being disposed between the motor gear and the support roller gear to avoid the building up of forces therebetween.
Roll-up doors are well known in the door art. Usually, such roll-up doors include a series of adjoining slats which are hingedly interconnected so that the slats can pivot relative to each other when the door is raised and rolled onto a support roller. Opposite ends of the slats are disposed in side rails within vertically disposed tracks so that the slats can ride up and down when being raised and lowered. Generally, the only type of thermal protection provided in the prior art roll-up doors is in some form of insulation provided on the slats to prevent a heat loss therethrough. Such insulation is usually of the foam type which is sprayed or applied in block form to the slats. In many cases, the slats are formed with hollow recesses therein to receive such insulation.
The roll-up and roll-down prior art mechanism usually includes a conventional motor which drives a gear. The motor gear is usually connected by a drive chain to a gear provided on the support roller so that the motor can rotate the support roller when activated to either raise or lower the roll-up door. However, during cold weather conditions, the support roller can become fixed in place or difficult to rotate. The play in the drive chain, which connects the motor gear to the support roller gear, causes the forces between the support roller and the motor to build up when the support roller cannot be freely rotated, thus causing damage to the support roller and/or the motor and/or the gears therebetween.
Accordingly, there is presently a need for a roll-up door provided with thermal protection means disposed in the mounting arrangement on opposite sides of the roll-up door, additional thermal protection means provided for the support roller on which the roll-up door is rolled up upon, and also for a roll-up door provided with a direct drive gearing arrangement between the roll-up and roll-down mechanism of the roll-up door, particularly between the motor thereof and the support roller therefor.